The Hidden Child
by FanndisLokidottir
Summary: Odin stole Loki Laufeyson from Jotunheim after the battle to unite the two kingdoms. But Loki wasn't the only child hidden in the temple that day. Loki's younger twin, Eira Laufeydottir had been hidden in a secret chamber under the temple, and was raised as a Jotun princess. So what happens when she travels to Midgard with Thor?
1. Prologue

**Author's Note:** This chapter is a summary of Eira's childhood. I am new at fanfiction writing, so I will gladly accept constructive criticism. And, as many people have written before me, I do not own anything that you recognize from the Avengers, Thor, and the Marvel Universe. Any similarities to other stories are unintentional.

Hope you enjoy it!

* * *

As Odin stared down at the Jotun child in is arms, he imagined the possibilities and opportunities that taking in this child, Loki, could bring to his realm of Asguard. Any audible cries from Loki's younger twin, Eira, were drowned out by the piercing sounds Loki was emitting. The muffling of her cries were due to the several feet of stone separating the chamber Eira was hidden in from the main room that Odin stood in.

When Odin left, the two siblings, born with the bond of being twins, were separated from each other in childhood. Neither would see each other for centuries, and only one would learn of the other before their first meeting.

* * *

In her childhood, Eira was a happy young girl. She was mischievous, cunning, intelligent, and chaotic while also being brave, selfless, kind, and merciful. However, there was an unexplainable feeling of loss and emptiness in her heart. She learned to distract herself by educating herself in essential subjects such as mathematics, history, geography, several languages, astronomy, science, and so on while also practicing magic and learning how to fight, the ways of a warrior, battle strategies, how to rule a realm, and other essential subjects for a future ruler of Jotunheim.

By the Jotun age equivalent of a human thirteen year old, Eira was able to match scholars in debates on aforementioned essential subjects, apply her knowledge to practical situations, best the greatest warrior in Jotunheim, and manage the kingdom, not to mention that she was the most powerful Mage in the history of her realm.

But no matter what she did, that feeling of loss and emptiness remained.


	2. A Secret Revealed, a Child is Lost

When Eira's father, Laufey, was murdered, she mourned his death, for he had been the best mentor she had ever known, even if he had never really been a good father. Then secret of her twin, Loki, and his part in Laufey's death was revealed to her.

* * *

Her coronation was celebrated with banquets, dances, and festivities. As she sat in the throne, holding the staff (which was the symbol of the King, or in this case, Queen), Eira couldn't help but shed a silent tear as she suddenly felt an onslaught of emotions that weren't hers. Why would she feel hopeless and vengeful and broken on her coronation day?

"Eira."

Withoit looking, she knew it was her only remaining parent, Farbauti, that had spoken, for no other in her kingdom would dare address her as such. "Rise, elder." As he rose, Eira touched her magic to Farbauti's to check that it was not an imposter. "Guards, you are dismissed."

"Yes?" She asked, turning back to Farbauti.

"There is a secret. One that Laufey and I promised each other to keep from everyone until the right time." Farbauti was nervous, although it was undetectable by all but those who had known them for their whole lives, like Eira. This set her on edge, for Farbauti was only nervous when he had good reason to be.

"Do you remember from your lessons the war in which we lost the Casket of Winters?" Seeing Eira's nod and raised eyebrow, he continued. "It was not the only thing stolen from us." Eira's eyes widened fractionally before she regained control of her expression, but it was still noticed by Farbauti. However, he could see the spark of anger in her eyes. Secretly praring himself for the impending disaster, he forged on.

"When Laufey and I discovered that we would soon have a child, we were overjoyed. We prepared a nursury, with everything that a child could ever want for. Then, at your birth, we found a second surprise: we had been gifted with not one child, but two. You, and your elder brother Loki. Both of you, as you probably know, were born smaller than most Jotun children, but it mattered nothing to us.

"Laufey and I wanted nothing more than to celebrate with feasts and festivities, but it was during the war. The palace was attacked, and we ordered the midwife to hide both of you in the chamber below the temple. There was only time for you to be hidden before a warrior entered the temple. Loki lay on the floor, looking as an abandoned babe would. The warrior, Odin, took your brother."

"Is...he dead now, elder?" Eira asked, secretly hoping that the answer was no. A twin bond was one of the most powerful, and explained the empty feeling she had grown accustomed to.

"No." Replied Farbauti. Eira subtly sagged in relief. "He has been raised as a prince on Asgard."

Suddenly, a messenger ran into the room. Kneeling, he said: "Your Highness, I have news from Asgard."

"Rise." Replied Eira, as decorum required. "What news do you bring?"

"My Queen," the messenger replied as she stood, "It is said that Prince Loki has fallen into the Void after a quick battle between himself and Thor. The Bifrost has also been destroyed."

Eira quickly applied an indifferent mask before her emotions could show. "Have a group of servants and four guards prepare for a trip to Asgard. Farbauti and I will travel with them to give our condolences. Dismissed."

The messenger left the throne room, leaving Eira and Farbauti alone again. A silence followed, until it was interrupted by Eira.

"I felt his emotions, earlier. Through the twin bond. He was so...broken inside when he fell. And he wanted revenge."

Farbauti looked at her, and said "I think you should spend some time to think about this. Pay attention to any feelings that come through. Although no one has ever been known to escape the Void, it does not mean that all who have been lost to it perished." And with that, Farbauti left Eira to her thoughts.


	3. An Alliance is Made, A Child is Found

**Author's Note: **Hi! Thanks to for my first review! I look forward to where this goes too! Anyways, I realized that in the previous chapter, Eira's coronation day is the day that Laufey died, because Laufey died minutes before Loki fell into the Void. I'm sorry if it bothers you, and if you want it fixed then post a complaint in a review, and I'll fix it. Continuing...

* * *

2 Days Later:

"Allfather. I offer my condolences for the loss of your son." Eira knelt on the floor before Odin, pausing unnoticeably before the word "son." If Loki could ever feel sad, _broken_ as she had felt through the bond, then Odin had obviously favored Thor, and not been a good father or a good mentor to Loki.

Continuing another focusing on the present, Eira said: "I hope that the peace treaty between our realms can be made to last for many decades to come."

Odin's eyes sparked with curiosity at this statement. "What...peace treaty?"

This surprised Eira. She raised an eyebrow. _He didn't know? I can use this to my advantage. _"Loki and my predecessor, Laufey, organized a contract between our two realms. In exchange for the passage of a few warriors and Laufey himself to Asgard, peace, and a possible alliance, could be brought between the two realms. As it is an active treaty, I believed that you had been aware of it."

Eira suddenly realized that she had brought up the subject of the assassination attempt. "I would also like to formally apologize for the actions of my predecessor."

Odin had an unidentifiable look on his face for a moment, then replied: "Your apology is accepted. I understand that you had no control over Laufey's actions." He paused. "Speaking of Laufey, he was your father, was he not?"

Eira had remembered something. "You have a son, Thor, if I recall correctly?"

Odin reacted as she had hoped. "Yes. After losing Loki, he is not only my firstborn, but the sole heir to my throne. Would you like to meet my son and my wife?"

"Of course." Replied Eira. It would be interesting to meet the future ruler of Asgard.

* * *

Kneeling, Thor spoke. "Your Highness, it is an honor to be in your presence."

Introducing Eira to his son, "Queen Eira, may I present my firstborn son and sole heir to the throne, Prince Thor." Odin then turned towards Frigga and said "And this is my wife and Thor's mother, Queen Frigga."

Nodding her head in acknowledgement, "And it is a pleasure to finally be able to mare your acquaintance. May your lives be long and joyful." Eira said, returning the proper reply as proper courtesy required. According to the tales that Farbauti had told her of Frigga, she had been a much better mother to her, and her kindness showed in her every action. Eira decided that if she had to choose an ally on Asgard, this woman would be her first choice.

"How long will you be staying? Are your quarters acceptable?" Yes, this sorceress wpuld definitely be her first choice.

* * *

1 Year Later:

The same messenger who had brought the news of Loki's fall ran back in. She had been promoted for her speed and accuracy, and so had been promoted. She now handled all communications between Asgard and Jotunheim, who had become close allies. Kneeling, she relayed the message.

"Hemdiall has seen Loki." Eira couldn't help it. Her eyes widened and her eyebrows shot up, even with her excellent masks. She had never lost hope that her brother had survived, and would find a way to escape the Void. "He is on Midgard. The Allfather requests the a warrior of Jotunheim to accompany Thor on a trip to see what he is up to and to return him to Asgard."

"Tell Farbauti to come to the throne room. Then send message to Asgard that the best warrior available will be sent on the morrow. Dismissed." By the time that the messenger left the room, Eira had already decided that she must go herself. Not only was she the best warrior and Mage that Jotunheim had ever seen, she had to go see what had become of her brother, and what he was like now.

Farbauti entered the throne room, and knelt. "Eira. Why have you called me today?"

"Rise, elder." She then relayed to Farbauti what her messenger had told her.

"I have decided that I will go as the requested warrior. You will take the throne until my return. In the possible situation that I cannot return for whatever reason, you will take my place on the throne and choose a proper heir." Farbauti looked like he wanted to object, but when Eira gave him her death glare, he sighed and gave in.

"Yes, your Majesty." Eira recognized the term as a sign of his dislike of her decision. She handed him the staff that identified the current ruler of Jotunheim, and knelt before him.

As he sat on the throne, Farbauti spoke the last words that he would say to Eira before she left. "Good luck, Eira. Dismissed."

As she left, Farbauti wondered of he would ever see Eira again.


	4. A Path is Chosen

**Author's Note:** Hello again! I'm really glad that people like my story. I was a little hesitant at first because this is my first fanfic, but it seems to be going pretty well. Oh, and something you should know is that I don't have a beta, and I probably won't ever get one. But, I might if my story gets popular.

Anyways, on with the show!

* * *

As the herald announced Eira's entrance, the Allfather and Thor paused in their discussion. "Thank you, Eira, for sending a warrior to us to help return Loki to Asgard." Quickly looking around the throne room, Odin allowed a curious look to pass over his face. "If I may ask, who is the warrior that you have sent? Is he or she standing outside?"

Inwardly smirking at the identical looks on the faces of both father and son, Eira replied. "No, Odin. Because of his relationship to you and his relationship to my late father, I have decided that I shall be the warrior to accompany Thor on his quest."

Seeing Odin prepare to object, she interrupted him before he could begin to speak. "I have made sure that my affairs are in order in the possible situation that I am unable to return to Jotunheim. Farbauti has been put in charge in my absence. Everything has been prepared for my journey to Midgard."

Odin seemed conflicted for a moment, and then he came to a decision. "Eira, Thor, the quest is to travel to Midgard, retrieve Loki, and repair any damage done in the process. Do you accept?"

Upon hearing both Eira and Thor declare "I accept," Odin gave them the specifics. "Loki has agreed to work with the Chitauri. They seek the Tesseract, which currently resides on Midgard. If it is acceptable, you will leave as soon as possible. Are you ready?"

Although she showed no emotions except for determination, inside Eira was excited and nervous. _I shall finally meet my brother!_ she thought. _At long last. _

Odin lead the team to the Rainbow Bridge, where Hemdiall awaited them, standing before a circle of runes.

"This is your last chance. Are you both sure that you are ready?" Eira quickly puts up a glamour, one that will disguise her as an Aesir, and nods. Seeing their Odin began channeling power into the rune circle as Eira and Thor stepped in. Very well then. I wish you birth good luck." Then, Odin began a short chant. As the energy in the air built up, Eira smiled. She would finally meet her brother, the Lost Child.

* * *

As Thor looked around, trying to figure out where they were, Eira performed a glamour charm to make her look human, and a short but powerful locator spell. She turned to Thor. "Loki is northwest of here. Do you want to fly, or should I teleport us there?"

Thor looked surprised at Eira's power, but answered her. "If it is faster, then you may teleport us." He accepted the hand that she offered him, and they disappeared.

* * *

20 miles from Stuttgart, Germany.

The pair reappeared in a forest, as a flying machine that Eira recognized from her studies as an airplane passed over them. Feeling a magical signature that was similar to hers, she realized that Loki had been captured by the mortals of this realm. After informing Thor of Loki's location, she teleported onto the plane and stamped on the door in place of a knock. When a door opened, she stepped in, assessing the people inside of the airplane.

"Greetings from Jotunheim and Asgard. I am Eira, and-" She was interrupted by lightning as Thor landed on the aircraft. "I am here with Thor of Asgard to return Loki to his home realm." Loki looked perfectly calm, but a brief brush against his magic told Eira that he was a little unnerved by her presence. He must not have expected an unknown person who was not of Midgard, and definitely not one of her caliber.

"Alright ma'am, but he just led an attack that killed at least forty people, so we're taking him back to our base first." This was spoken by a man with fair hair wearing a colorful skintight suit. Thor nodded, realizing that it was essential to the cooperation of this group later. Eira was impatient to return her brother to Jotunheim, and to learn more about him, but she knew that in order to do this, she would have to bide her time.


	5. A Battle is Lost, a Warrior is Saved

**Author's Note: **Hello readers! Sorry about the lags between updates; my muse hid from school, and it took him a while to be coaxed out of my closet. Also, in Chapter 3, I'm changing it so that Eira is pretending to be an Asgardian to reduce possible suspicion from Loki.

Also, I'm going to cut out a couple of scenes from the Avengers because I don't want to go through all of them and copy down everyone's movements and lines. You can just remember them if you've seen the movie.

By the way, this chapter is going to be Eira's POV.

"English"

"_Norse"_

_thoughts_

* * *

"What's his play?"

I mentally sighed. It's quite obvious from the speech that he gave that he wishes to control all of Midgard. "Loki has made a deal with a being called Thanos. In return for the Tesseract, Loki has been given an army of the Chitauri. He will lead them in a bid to control Midgard."

"So, what do we do?" This came from Stark, who had produced a bag of blueberries out of seemingly nowhere. Had I not seen him untape it from the bottom of the table. Agent Romanoff sent him a look.

"Thor and I shall take him back to Asgard, to have a trial and face Asgardian justice."

Stark immediately made to object, looking up from his screens for a moment. "Hey, Loki killed 80 people in two days. He's not going anywhere until he faces us." A beeping noise goes off. "Guys, we've got the locatio-"

Suddenly, an explosion rocks the helicarrier.

* * *

"_Brother, no!_" I just manage to finish my scream before Loki charges at Agent Coulson. Reacting as fast as I can, without thinking about my own health, I teleport in front of Coulson just before the scepter plunges into my chest. Excruciating pain tears through my body as my glamour falters for a moment, revealing my heritage to Loki. His eyes widen fractionally for a moment, before he pulls the scepter from my chest and steps back, in eyes close hard as I begin hacking up blood, a small pool forming below my cheek.

A pair of strong arms wrap around me, and lifts me up. I notice that something painfully digs into my back, but it is pushed to the back of my mind as the pain from the gaping wound in my chest multiplies for a moment, before a quiet but strong voice whispers something and I fade out of consciousness.


	6. A Battle is Won, A Child is Freed

**Author's Note:** Hey guys, girls, and everyone else that I haven't mentioned. Sorry that the updates are slow, I'm going to try to speed them up again. But, this is my longest chapter yet, at 1,787 words! That's more than twice the length of any of the other chapters!

Feedback or suggestions for the story would be greatly appreciated, because this is my first fanfic. Real quick, should I start a new story where Thanos himself leads an invasion, and his lieutenant is the POV of the main characters?

See previous chapters for meanings of italics, etc.

_Emphasized words_

* * *

Original POV

Thor stood alone in a field, praying to his father that everyone else who had not been harmed in the first explosion had not been harmed in the following battle. When he thought of Eira, however, he realized that he had begun to enjoy her visits to Asgard, and perhaps look forward to them.

He remembered what had happened just before Loki had pressed the release button: Coulson (who he joked with by calling him 'Son of Coul') had rushed into the room, holding a rather large weapon similar to the one that the Captain had dropped on the table before the earlier argument.

Suddenly, Thor realized that he was not holding Mjölnar, and turning he saw it laying a few yards away. He reached down, but paused for a moment, wondering if he was still worthy even if he had been part of the reason for Loki's actions. But then, he thought of Coulson, and Stark, and Eira, and everyone else who he had met, and his need to help them overcame his fear.

He lifted Mjölnar.

* * *

Loki's POV

It had been weeks, almost months, since he had moved. Yes, his body moved, but not by his own will. He could almost feel the darkness on the other side of the wall in his mind, controlling everything: his body, his voice, his magic, _everything_.

And the worst part was not the lack of control. He could have taken that for a little while longer. But he could see everything that his body was doing, and do nothing but feel helpless about it. And being helpless was the feeling he loathed and feared the most.

So he watched. And he waited. And slowly, he died a little more each passing moment.

* * *

Original POV

_She could hear a child's laughter in the background. "Again, daddy!" She giggled. Farbauti smiled, and conjured little butterflies out of ice, and animated them with his magic. She shrieked with laughter, holding out a hand for the little toys to land on. _

Suddenly, Eira was jerked out of her memories by pain. Unfiltered, searing pain radiating from her chest. Hissing through clenched teeth, as she feels her ribs grinding against each other, shifting back in place, and the muscle tissue grew and knitting itself back together again. Finally, the upper layer of skin seals and the last clearly visible evidence of her wound disappears except for a faint, thin scar where the hole in her chest had closed last.

Finally able to lay flat and relax her muscles, Eira lay silent, reaching out with her magic to observe the room without giving the appearance of taking in her surroundings. It's a well decorated room, with expensive furnishings. What catches her attention, however, is the other living being in the building with a magical core.

It feels strange, as if someone had weakened the original mind, and inserted a parasite that fed off of the body. Curious, Eira opens her eyes.

A pair of electric blue eyes stares back. "Hello," says the owner of the unnaturally blue eyes. "Who are you?"

The parasite feeds off of the body as the man who she now recognizes as Loki speaks.

"I am no one." Eira knows that her brother would not believe her, and the parasite doesn't either.

"Really." Says the Parasite. "Well then, I suppose I have no use of you," it says, deciding to play along. It raises the staff that glows the same blue as it's eyes, and presses it against Eira's chest.

The Parasite's twisted power flows through her body from her chest, trying to push her mind into a corner. However, it was still the magic of her twin, albeit corrupted by the Parasit and the Tesseract, and so couldn't do anything more than give the appearance of being under the Parasite's control.

Eira, realizing this when the Parasite steps away and gives her the order to defend the Tesseract, decides to play along to find out more about the Parasite. "Yes, my lord." She turned around and quickly strode out of the room into the hallway. From there, she entered the elevator, going to the top floor where she could feel the energy of the Tesseract radiating from.

Once there, she sees the compromised scientist that had been mentioned by the agents on the Helecarrier. "Dr. Selvig?" she calls. He doesn't turn away from his work on the complex portal device, but acknowledges her presence with a nod in her general direction. Suddenly, he jerks his eyes away from his device and turns to her, robotically standing up.

"Who are you?" He looks perplexed, as if unsure of whether or not he should trust Eira. _Perhaps it is his human nature telling him to trust me, _she thinks, _but the lack of traces of the Tesseract's power in my mind that makes him wary of me._ Deciding to take advantage of his confusion, Eira replies.

"My purpose is to guard the Tesseract and anyone working with it." Selvig relaxes, and turns back to the Tesseract, continuing his job.

* * *

Twenty Minutes Later:

Dr. Selvig looks up at Eira. "It's ready!" He laughs, but it isn't a laugh of joy. It rings of the desire to hurt and maim and kill. Eira begins walking to her, and is only a couple of steps away when Selvig continues: "It wants to show us something!"

Eira is at Selvig's immediate right when he reaches forward to place the final component in: the energy source, the Tesseract. Before he can get it into place, Eira shoots a blast of ice at the center of the machine, destroying a good hour of work and disabling the device.

Dr. Selvig cries out at the loss of what must be his most complicated piece of work, but Eira ignores his attempts to stop her from causing more destruction to his masterpiece and forces the ice to grow, crushing some parts, punching gaping holes in others, and twisting the remaining hunk of metals into a sculpture of her late parent and mentor, Laufey, to both create a tribute to Laufey and also to attempt to get a hint of her identity to her brother without alerting the Parasite.

As she finishes sculpting the staff in the late King's iron fist, the Parasite in Loki's body steps out onto the rooftop, and stops for a moment, shocked at the scene that was before him. The Aesir, Eira, that had been under his control stood before a metal sculpture of what was clearly Laufey, using magic to warp the portal device's shape, ignoring the man that was punching and kicking and screaming at her.

The Parasite was angry. It raises its staff, determined to destroy the being that dared to interfere with its plans. The sphere of energy barely misses Eira due to the Parasite's anger and hate, but hits a section of floor between Eira and Selvig, launching sharp shards of concrete into the air in a way similar to the pattern on a land mine.

Eira ducks behind the statue of Laufey, which rings with the clanging and screeching of metal on metal, but Selvig isn't as lucky. Eira winces at the sight of Selvig's face, tight with pain even after being knocked out, not because of the red flowing down his face, but for the that fact she cannot heal the jagged slices that mar his face. Quickly, she casts several spells to clean and heal Selvig's face before she turns to find where the Parasite is now.

She spots it aiming its scepter at one of SHIELD's aircraft, and quickly runs to tackle the Parasite. The aim is thrown off, and it hits the building to the right of the aircraft. As it flies closer to Stark Tower, as she had found out the building was called while waiting with Selvig, she sees that it contains Agent Coulson, a muscular man that she recognized from SHIELD files as Agent Barton, and all but two of the Avengers.

It lands a little more than 10 feet away from Eira and Loki, who are now wrestling on the floor, each trying to keep the other from casting any spells. The Parasite, which seems dependent on the staff that is now fifteen feet away, is losing, and Eira sees an opportunity to end this fight. "Forgive me, brother," she whispers.

Eira slams Loki's head into the ground, and his muscles immediately loosen in unconsciousness. Her ability to feel Loki's emotions, which had been almost nonexistent for the past eight months, allows her to feel a sudden flare of joy and relief before his mind fades into darkness.

Reaching out with her magic into Loki's unguarded mind, she discovers that the Parasite's hold on her twin has loosened. Not one to decline a perfect opportunity, she enters his mind and carefully pulls the Parasite out, and feeding her magic to her twin's mind to strengthen it. Pulling away, tells the Avengers and SHIELD agents that she will deal with Loki, but that they will need to guard the Tesseract and take it back to SHIELD for temporary safekeeping, until it could be taken back to Asgard.

After Iron man convinces everyone else to go to the shawarma place down the street, Eira is truly alone with her twin for the first time. She weaves a pattern of healing spells around him, returning his body to almost perfect health in minutes, then cleans up and repairs his armor and clothing to make him look presentable. After making sure that nothing would cause permanent damage to her twin, Eira delves back into Loki's mind to remove any traces of the Parasite and the Tesseract's powers.

When his eyes open by his own command nearly half an hour later, Loki's eyes are a beautiful dark green that flawlessly match his worried twin's tear-filled eyes.


End file.
